Effectiveness and Implementation of a National Guideline for Acute Respiratory Tract Infections to Reduce Antibiotic Prescribing in Swiss Primary Care

The ImpProGUIDE study aims to find out whether implementing new Swiss national guidelines for acute respiratory infections (ARI) can help to reduce antibiotic prescribing in primary care. In Switzerland, most antibiotics are prescribed in outpatient care, and many of these prescriptions may not be needed - especially when infections are caused by viruses, which antibiotics do not treat. Reducing overuse of antibiotics is important to slow the spread of antibiotic resistance. The new guidelines were developed by the Swiss Society for Infectious Diseases (SSI) to support family doctors in managing ARIs, based on a syndromic approach. They recommend the targeted use of point-of-care C-reactive protein (CRP) testing when bacterial infection is suspected, as well as shared decision-making with patients. This study will be carried out in quality circles (QCs) - small groups of family doctors who meet regularly to discuss and improve clinical practice - and in walk-in clinics in French- and Italian-speaking regions of Switzerland. Each will be randomly assigned to either an "intervention" group or a "control" group. In the intervention group, QC moderators and medical center directors will receive implementation resources to lead a session and distribute materials to their group in autumn 2025 on the new guidelines. Doctors can then decide whether or not to use the recommendations in their consultations. In the control group, QCs and centers will continue their regular activities. They will receive access to the same educational materials later, in summer 2026. Throughout the study, the researchers will collect de-identified data from health insurance billing records to track antibiotic prescribing and the use of diagnostic tests. Doctors and QC moderators will also be invited to complete short online surveys twice a year (10-15 minutes) and may be asked to join optional interviews or group discussions after the winter season. The study will also explore the effectiveness of the implementation strategies on the adoption of the SSI guidelines, as well as the barriers and facilitators to adoption. This study type is known as a hybrid effectiveness implementation study, simultaneously evaluating an intervention's impact on antibiotic prescribing and the strategies used to implement the new national guidelines in a real-world setting. Participation in the study is voluntary. Doctors can withdraw at any time. All data will be handled confidentially and in line with Swiss data protection laws. The study is funded by the Swiss National Science Foundation. No support is received from pharmaceutical companies or manufacturers of diagnostic tests.